In wastepaper recycling, the raw material, namely, the scrap paper fibers, tend to become damaged during the recycling treatments. A paper fiber can be used some four to six times before it breaks and becomes unusable As a consequence of such breakage, the production water used in the recycling of wastepaper becomes enriched in fiber particles and, in the process, the fiber particles are collected from the production water, e.g. by floatation and the collected material is dewatered to form a concentrate which consists predominantly of such particles which are wood and cellulose fibers and thus consists predominantly of cellulosic material This collected dewatered product is referred to herein as "the collected product."
In the wastepaper recycling process, moreover, there also arises a material which will be termed herein a "residue" and which consists predominantly of plastic particles or pieces. This residue present in the original scrap paper is separated out prior to the waste paper processing and may be in the form of adhesive tapes or strips, plastic foils and the like. Indeed, such residues generally consist of more than 95% by weight of plastic pieces and are directly separated from the recycling process and generally must be disposed of independently from the collected product described above The residue is also termed the "reject" in the trade.
In the past, the collected product, dewatered to a dry solids content of about 35%, is disposed of in a landfill. The residue is likewise generally disposed of in a landfill independently from the collected product.
If one appreciates that about 10% of the scrap paper at the start of wastepaper recycling is in the form of the collected product and the residue and that the weight proportion of the collected product to the residue is about 9:1, it should be immediately apparent that, for ecological reasons, wastepaper recycling, although laudable in enabling reuse of a high-bulk material, poses a significant danger to landfill capacities.
As a consequence, as ecological forces in society increasingly promote wastepaper recycling, there is created a substantial challenge to existing landfill capacities which are rapidly being depleted Consequently, it should be clear that another approach to the disposal of the collected product and the residue, as defined above, from wastepaper recycling is essential.